A Method to Represent a Well in a Three-Dimensional Discrete Fracture Network Model

Area of Science:

• Geosciences
• Hydrogeology
• Computational modeling

Background:

• Discrete fracture network (DFN) models often simplify or omit wells, leading to disconnects between wells and the hydraulically active fracture network.
• Ignoring smaller fractures and isolated networks in DFNs can result in large impermeable rock matrices and poor well connectivity.

Purpose of the Study:

• To develop and validate a novel method for incorporating wells into 3D DFN models.
• To enhance the accuracy of flow and transport simulations by ensuring well connectivity to fracture backbones.

Main Methods:

• Conceptualized wells in 3D DFNs using two orthogonal rectangular fractures aligned with the well axis.
• Introduced six parameters to define well screen, skin zone, and connectivity to fracture backbones.
• Discretized fractures with a high-resolution mesh for improved simulation quality and implemented within dfnWorks 2.0.

Main Results:

• Successfully incorporated wells into 3D DFNs, enabling particle tracking between injection and pumping wells.
• Verified the method against MODFLOW/MODPATH, achieving perfect agreement in hydraulic head and particle tracking simulations.
• Demonstrated the method's ability to ensure well-fracture connectivity and accurately represent flow and transport processes.

Conclusions:

• The developed method effectively integrates wells into DFN models, enhancing simulation accuracy.
• The approach provides a robust framework for understanding fluid flow and solute transport in fractured porous media.
• Recommendations are provided for parameter estimation in real-world applications.